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Beam Deflection

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Date Issued:
2013
Abstract/Description:
In order to fully understand the third order nonlinear optical response of materials under high irradianceexcitation it is necessary to study the temporal and polarization dependence of nonlinearrefraction and absorption. There are several existing approaches such as Z-scan and pump-probetechniques to determine those responses. As part of this work, these approaches will be briefly outlinedbefore presenting beam deflection, applied from photothermal beam deflection, as an alternativeexperimental technique to determine the nonlinear refraction with its temporal and polarizationdynamics. This technique measures the angle of the probe beam deflected via the index gradientof the material induced by strong excitation beam, to determine both the sign and magnitude of thenonlinear refraction. The temporal and tensor properties of the nonlinear refractive index can bedetermined by introducing a delay line, and by varying the polarization of the excitation and probebeam, respectively.To demonstrate the practicality of the beam deflection technique, we performed measurements onFused Silica, Carbon Disulfide and Zinc Oxide. Each of these samples shows quite different nonlinearresponses. Amorphous fused silica exhibits nonlinear refraction purely from instantaneouselectronic contribution; while Carbon Disulfide shows a much slower response, originating notonly from the electronic contribution but also from non-instantaneous nuclear movements (e.g.molecular orientation). These two contributions can be separated by varying the polarization directionof the excitation and probe beam. By introducing lock-in detection technique, a sensitivityof λ/5500 can be achieved. In Zinc Oxide, a wide-bandgap semiconductor, we measure bothnonlinear refraction and two-photon absorption simultaneously. Therefore the beam deflection isa sensitive technique, which can be used to measure the time and polarization dynamics of thenonlinear response of the material.
Title: Beam Deflection.
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Name(s): Münnich, Matthias, Author
Hagan, David, Committee Chair
Vanstryland, Eric, Committee CoChair
Dogariu, Aristide, Committee Member
, Committee Member
University of Central Florida, Degree Grantor
Type of Resource: text
Date Issued: 2013
Publisher: University of Central Florida
Language(s): English
Abstract/Description: In order to fully understand the third order nonlinear optical response of materials under high irradianceexcitation it is necessary to study the temporal and polarization dependence of nonlinearrefraction and absorption. There are several existing approaches such as Z-scan and pump-probetechniques to determine those responses. As part of this work, these approaches will be briefly outlinedbefore presenting beam deflection, applied from photothermal beam deflection, as an alternativeexperimental technique to determine the nonlinear refraction with its temporal and polarizationdynamics. This technique measures the angle of the probe beam deflected via the index gradientof the material induced by strong excitation beam, to determine both the sign and magnitude of thenonlinear refraction. The temporal and tensor properties of the nonlinear refractive index can bedetermined by introducing a delay line, and by varying the polarization of the excitation and probebeam, respectively.To demonstrate the practicality of the beam deflection technique, we performed measurements onFused Silica, Carbon Disulfide and Zinc Oxide. Each of these samples shows quite different nonlinearresponses. Amorphous fused silica exhibits nonlinear refraction purely from instantaneouselectronic contribution; while Carbon Disulfide shows a much slower response, originating notonly from the electronic contribution but also from non-instantaneous nuclear movements (e.g.molecular orientation). These two contributions can be separated by varying the polarization directionof the excitation and probe beam. By introducing lock-in detection technique, a sensitivityof λ/5500 can be achieved. In Zinc Oxide, a wide-bandgap semiconductor, we measure bothnonlinear refraction and two-photon absorption simultaneously. Therefore the beam deflection isa sensitive technique, which can be used to measure the time and polarization dynamics of thenonlinear response of the material.
Identifier: CFE0004896 (IID), ucf:49653 (fedora)
Note(s): 2013-08-01
M.S.
Optics and Photonics, Optics and Photonics
Masters
This record was generated from author submitted information.
Subject(s): NLO -- Beam Deflection
Persistent Link to This Record: http://purl.flvc.org/ucf/fd/CFE0004896
Restrictions on Access: public 2013-08-15
Host Institution: UCF

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